Diabetes is a huge and growing problem—affecting one in every 19 people on the planet. But you may not be familiar with the daily struggle that many people with diabetes face as they try to keep their blood sugar levels under control. Uncontrolled blood sugar puts people at risk for a range of dangerous complications, some short-term and others longer term, including damage to the eyes, kidneys and heart. Google is now testing a smart contact lens that’s built to measure glucose levels in tears using a tiny wireless chip and miniaturized glucose sensor that are embedded between two layers of soft contact lens material. There is an early warning for the wearer, a tiny LED lights will light up to indicate that glucose levels have crossed above or below certain thresholds. These lens will have chips and sensors so small they look like bits of glitter, and an antenna thinner than a human hair—might be a way to crack the mystery of tear glucose and measure it with greater accuracy.